[Akutsu, YokozaWashimi]

This morning (8:30~9:00 JST), we performed the tapping test in the PSL room. We found 2 remarkable things

1. High power laser: when we tap the optical table near the high power laser, peaks around  400 Hz are excited.
2. Beam duct: when we tap the beam duct going to the MCF chamber, the "shoulder shape" noise was excited. However, there is no excited noise when we put the shaker (60-2000Hz broadband) on the duct.
3. A cable connected to the final periscope was not sensitive to the DARM

We could not find something when we tap other places. (We did not touch any optics.)